666777 has 8 divisors (see below), whose sum is σ = 913216. Its totient is φ = 432432.

The previous prime is 666773. The next prime is 666811. The reversal of 666777 is 777666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 666777 - 2² = 666773 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 666777.

It is not an unprimeable number, because it can be changed into a prime (666773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2893 + ... + 3114.

It is an arithmetic number, because the mean of its divisors is an integer number (114152).

2⁶⁶⁶⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

666777 is a deficient number, since it is larger than the sum of its proper divisors (246439).

666777 is a wasteful number, since it uses less digits than its factorization.

666777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6047.

The product of its digits is 74088, while the sum is 39.

The square root of 666777 is about 816.5641432245. The cubic root of 666777 is about 87.3628654600.

Subtracting 666777 from its reverse (777666), we obtain a square (110889 = 333²).

The spelling of 666777 in words is "six hundred sixty-six thousand, seven hundred seventy-seven".